VISA Problem.

[john7]

I have a problem. When i  turn on my PC - no serial communication with VISA. I go Measurement & Automation - Devices & Interfaces - Ports(Serial & Parallel) then i exit and all work just fine - till next PC restart. How can i do "refresh" automaticlly?

[nyc_(is_out_of_here)]

Is this a real serial port or are you using somesort of USB-serial adapter?

[JÞB]

---

@nyc_(is_out_of_here) wrote:

Is this a real serial port or are you using somesort of USB-serial adapter?

---

Of course its a Virtual Com port.  And, the Windows Power Manager options are set to shut down the HUB Power.

Some tips on USB can be found here

[john7]

Yes, it's USB to RS232 convertor (FTDI chip). I've uncheked the save power option, still the same problem.

[nyc_(is_out_of_here)]

---

@JÞB wrote:

---

@nyc_(is_out_of_here) wrote:

Is this a real serial port or are you using somesort of USB-serial adapter?

---

Of course its a Virtual Com port.  

---

Why "of course"?

[JÞB]

---

@nyc_(is_out_of_here) wrote:

---

@JÞB wrote:

---

@nyc_(is_out_of_here) wrote:

Is this a real serial port or are you using somesort of USB-serial adapter?

---

Of course its a Virtual Com port.  

---

Why "of course"?

---

There is no way for any "COM" port to get lost from the OS (Well, no easy way you would need to disable it from the device manager and MAX refresh would not really help)  PCI bus resources really don't pop in and out of existance often despite being technically "Hot-swappable."    Assuming the vendor supported the corrent optional whizbangs and the BIOS doesn't get too confused-  (Read that as "Don't try this with your NI- PXIe chassis connected via MXI")

Some method of stopping a DcomLaunch group service would be much easier to believe. 

In the OP's case I would look to see if there is an updated FTDI driver for the OS in question if These services are running at start-up:

[nyc_(is_out_of_here)]

---

@JÞB wrote:

---

@nyc_(is_out_of_here) wrote:

---

@JÞB wrote:

---

@nyc_(is_out_of_here) wrote:

Is this a real serial port or are you using somesort of USB-serial adapter?

---

Of course its a Virtual Com port.  

---

Why "of course"?

---

There is no way for any "COM" port to get lost from the OS (Well, no easy way you would need to disable it from the device manager and MAX refresh would not really help)  PCI bus resources really don't pop in and out of existance often despite being technically "Hot-swappable."    

---

I suppose you were able to discern more from what the OP wrote than I was able to.

I have learned never to assume on this message board that what is written is what really is.

[JÞB]

---

@nyc_(is_out_of_here) wrote:

---

I suppose you were able to discern more from what the OP wrote than I was able to.

---

It helps to have a fair to middlen accurate magic 8-Ball (tm)

Or have gone through enough pain tring to get down at levels where COM ports can get wonky even from MAX

[john7]

But a terminal (i use Br@y) works fine, no problem. I suppose it's VISA issue.